Final answer:
Young adults between 18 and 29 have the highest rates of alcohol consumption in the U.S. and the National Minimum Drinking Age Act of 1984 requires states to enforce a drinking age of twenty-one to receive full federal highway funds.
Step-by-step explanation:
In the United States, young adults between the ages of 18 and 29 have the highest rates of alcohol consumption and make up the largest proportion of problem drinkers of any age group. The National Minimum Drinking Age Act of 1984 mandated states to raise their minimum drinking age to twenty-one, or they would risk a reduction in federal highway funds. This law has been subject to various interpretations and enforcements by the states. The origins of America's relationship with alcohol date back to colonial times and have been characterized by high consumption levels and subsequent social reform movements, such as the temperance movement in the 19th century and the work of organizations like Mothers Against Drink Driving (MADD) in the modern era.